The present invention relates generally to wrist braces, and more particularly, to a flexible wrist brace for alleviating the symptoms associated with wrist injuries, such as carpal tunnel syndrome and ulnar neuritis, without restricting the wearer's ability to grasp objects and perform daily tasks. Additionally, the present invention is directed to methods for alleviating and preventing wrist pain associated with such wrist injuries.
Many people suffer from injury to the soft tissues of the wrist and carpal tunnel, often caused by frequent, sustained repetitive motion involving the hands. Repetitive activities which require the same or similar hand/wrist action can result in injuries which have been collectively referred to as Cumulative Repetitive Stress Syndrome or Repetitive Strain Injury. The most familiar and common of such wrist injuries is known as carpal tunnel syndrome which produces pain, discomfort, nerve conduction disturbances, and impairment of function of the hand and sometimes the arm as well. The most common symptoms of this condition include intermittent pain and numbness of the hand.
Carpal tunnel syndrome occurs when the median nerve, which runs from the forearm into the hand, becomes pressed or squeezed at the wrist. The median nerve provides feeling in one's thumb, along with the index, middle and ring fingers. The median nerve controls sensations to the palmar side of the thumb and these fingers as well as impulses to some muscles in the hand which allow the fingers and thumb to move. The median nerve receives blood, oxygen and nutrients through a microvascular system which is present in the connective tissue surrounding the nerve fiber. Increased pressure on the nerve fiber can constrict these microvessels and will reduce the blood flow to the median nerve. Any prolong deprivation of oxygen and nutrients can result in severe nerve damage.
The median nerve passes through the carpal tunnel, a canal in the wrist surrounded by the carpal bones on three sides and a fibrous sheath called the transverse carpal ligament (“flexor rethinaculum”) on the fourth side. In addition to the median nerve, the nine flexor tendons in the hand pass through this canal. When compressed, the median nerve will cause pain, weakness or numbness in the hand and wrist which may also radiate up along the arm. The median nerve can be compressed by a decrease in the size of the carpal canal itself or an increase in the size of its contents (i.e., such as the swelling of the flexor tendons and the lubrication tissue surrounding these flexor tendons), or both. For example, conditions that irritate or inflame the tendons can cause them to swell. The thickening of irritated tendons or swelling of other tissue within the canal narrows the carpal canal, causing the median nerve to be compressed. The cross-sectional area of the tunnel also changes when the hand and wrist changes positions. Wrist flexion or extension can decrease the cross-sectional area, thus increasing the pressure exerted on the median nerve. Flexion also causes the flexor tendons to somewhat rearrange which can also compress the median nerve. For example, simple bending of the wrist at a 90° angle will decrease size of the carpal canal. Without treatment, carpal tunnel syndrome can lead to chronic neural muscular disorders of the hand and sometimes the arm.
While carpal tunnel syndrome is generally associated with repetitive motion involving the hands, physiology and family history may also play significant roles in a person's susceptibility to the injury. For example, the disorder is sometimes due to a congenital predisposition, namely, that the carpal tunnel is simply smaller in some people than in others. Other contributing factors include trauma or injury to the wrist that cause swelling, such as a sprain or fracture. Over activity of the pituitary gland, physiological problems in the wrist joint itself, work stress, fluid retention during pregnancy or menopause and diseases such as diabetes, rheumatoid arthritis or thyroid disease are still additional sources which may lead to the carpal tunnel syndrome.
Treatment for carpal tunnel syndrome may include non-surgical and surgical procedures. Treatments for carpal tunnel syndrome should begin as early as possible to prevent the occurrence of more severe symptoms. Non-surgical treatments include the restriction of the motion of the wrist by immobilizing braces or splints; controlling the pain and swelling by administering anti-inflammatory drugs, such as aspirin, ibuprofen and other non-prescriptive pain relievers; administering diuretics to decrease swelling; and injecting the wrist with pain killer such as corticosteroids or the drug lidocaine. Other non-surgical treatments include, but are not limited to, applying heat or cold to the effective site to promote repair of the injured tissue; performing physical therapy to the hand and wrist to reduce the stress on the wrist; adopting a more ergonomic work and life environment; and avoiding or curtailing the hand motion which produces the inflammation in the first place. If the symptoms cannot be treated with non-surgical intervention, then surgery may be required. Carpal tunnel release is one of the most common surgical procedures performed in the United States to treat carpal tunnel syndrome. This surgery involves severing the transverse carpal ligament to relieve the pressure on the median nerve. Surgery is usually done under local anesthetic and usual does not require an overnight hospital stay.
Another painful injury to the wrist is ulnar neuritis which, like carpal tunnel syndrome, results in numbness, tingly, a burning sensation and pain in the hands and fingers. The ulnar nerve, like the median nerve, can be impinged and irritated at the wrist. The ulnar nerve runs down the ulnar (small finger) side of the wrist. It supplies sensation to the small and ring fingers as well as controls some small muscles of the hand. Similar factors as those seen with carpal tunnel syndrome can contribute to ulnar neuritis. Direct pressure on the nerve for long periods of time, such as biking, is a significant contributor to the problem. Trauma or a fall on the palm may also bring about symptoms. The ulnar tunnel (also referred to as Guyon's canal) is a canal in the wrist that contains both the ulnar nerve and the ulnar artery. Compression of the ulnar nerve, like compression of the median nerve, can cause similar symptoms as carpal tunnel syndrome. This syndrome is much less common then carpal tunnel syndrome yet both conditions can occur at the same time. The numbness caused by these two syndromes effect the hand in different locations. When the median nerve is compressed in carpal tunnel syndrome, pain and numbness spread into the thumb, index finger, middle finger and half the ring finger. Compression of the ulnar nerve in the Guyon's canal usually causes numbness in the pinky and half of the ring finger. Non-surgical treatment for ulnar neuritis is similar to carpal tunnel syndrome. If all attempts to control the symptoms utilizing non-surgical techniques fail, then surgery may be needed to reduce the pressure on the ulnar nerve.
One way to prevent the onset of carpal tunnel syndrome is to prevent the swelling or inflammation of the flexor tendons (the flexor digitorum superficialis tendons and flexor digitorum profundus tendons) which extend through the carpal tunnel. Additionally, prevention of inflammation to the flexor tendon sheath and the lubrication tissue surrounding the flexor tendons will help to alleviate compression of the median nerve. Additionally, there are other tendons surrounding the carpal tunnel which also can become inflamed and swollen and could exert additional pressure on the median nerve. These tendons include the palmaris longus tendon, the flexor carpi radialis tendon and the flexor carpi ulnaris tendon. The palmaris longus tendon can become swollen and can cause additional pressure on the median nerve due to its close proximity thereto. The same is true of the flexor carpi radialis tendon. In the case of ulnar neuritis, should the flexor carpi ulnaris tendon become swollen and inflamed, its proximity to the ulnar nerve can be a source of increased pressure on the ulnar nerve. Therefore, the prevention of the inflammation and swelling of these wrist tendons serves as a good treatment for preventing carpal tunnel syndrome and ulnar neuritis.
The swelling and inflammation of the flexor tendons and tendons within in the wrist of a person is often caused by the stretching and outward movement of the tendons within the wrist as the wrist flexes and extends and fingers move. In this regard, the tendon has a tendency to stretch and move in an outwardly fashion away from the carpal bones in the wrist which can cause the tendon sheath, and the tendon itself, to become swollen or inflamed when this same motion is repeated again and again. This constant stretching of the tendon in both a longitudinal and an outward direction is a primary cause of the inflammation and swelling of the tendon and tissue in the wrist area. Prolonged and continuous subjection of the tendons to this repetitive motion only causes additional stretching of the tendons and surrounding tissue and only increases the pain. Irritation and swelling of the tendon can be alleviated by preventing the tendon from stretching and moving outwardly in the first place.
As mentioned above, one approach to lessening the pain associated with carpal tunnel syndrome and ulnas neuritis is to restrain the wrist to prevent the repetitive hand motions which cause the discomfort in the first place. In this regard, many wrist braces have been develop to address the need to confine the wrist and forearm in an immobilized position. While such braces or splints do somewhat reduce continued injury to the median nerve and ulnar nerve by restraining this wrist, such wrist braces and splints usually restrict the motion of the fingers and flexion and extension of the wrist. Such braces and splints can prevent the wearer from properly grasping objects and performing normal daily tasks utilizing the affected hand.
What have been needed and heretofore unavailable are improved wrist brace and methods for alleviating and reducing the adverse results caused by injuries to the wrist, such as carpal tunnel syndrome and ulnar neuritis. Such a device and method should eliminate the disadvantages and shortcomings associated with prior developed braces and splints. Preferably, the brace device should be lightweight and relatively simple in construction to allow the user to wear the brace device without much interference to the wearer's ability to flex the wrist and manipulate the fingers in a normal fashion. It should be designed so that the device can be easily placed on the hand with a minimal need to reposition the brace on the wrist in response to hand and wrist motion. Also, it would be beneficial and economical if the wrist brace could be worn on either hand of the individual. The present inventions disclosed herein satisfy these and other needs.